The Clinical/Pathology Core will continue to coordinate the collection of tissue and blood samples at the time of transplantation and at the time the allograft is biopsied. Tissues from the explanted hearts and from selected endomyocardial biopsies will be collected. Blood/plasma samples will be collected from donor, recipient, blood bank, and from the spouse of the recipient at the time of transplantation. In addition, this core will act as the repository for all the relevant clinical data in support of these tissue samples. This core will examine the collected tissue and blood samples using general histology, routine immunohistochemistry and specialized coagulation assays in support of individual projects. Finally, this core will provide non-routine noninvasive analyses. Cardiac surgeons at Johns Hopkins have transplanted 337 hearts into human recipients during the last 18 years (to 8/31/01) and the demographics of these recipients are: by gender-93 female, and 244 male; by race- 39 African American, 291 Caucasian, and 7 other; and by age-29 children and 308 adults. During the current period of this program project 86 hearts were successfully transplanted (by gender-29 female, and 57 male; by race-23 African American, 57 Caucasian, and 6 other; and by age-4 children and 82 adults). After transplant, surveillance endomyocardial biopsies are performed every 10 days for the first month, every 14 days for second month, every month for months 3 to 6, and every 4 to 6 months, thereafter. Additional endomyocardial biopsies are performed when the symptoms dictate. 180 heart transplant patients were followed during the most recent year (9/1/00-8/31-01) and 600 endomyocardial biopsies were performed.